make sure the engine's currentFrame is in sync when calling out to public API

The currentFrame pointer is used e.g. by QScriptValue::toString(). It needs to
be in sync, otherwise we will crash.

Reviewed-by: Olivier Goffart

2 files changed, 25 insertions, 0 deletions

diff --git a/src/script/api/qscriptengine.cpp b/src/script/api/qscriptengine.cpp
index 7a910d2..71194d3 100644
--- a/src/script/api/qscriptengine.cpp
+++ b/src/script/api/qscriptengine.cpp
@@ -508,6 +508,7 @@ JSC::JSValue JSC_HOST_CALL functionDisconnect(JSC::ExecState *exec, JSC::JSObjec
             slot = arg1;
         else {
             // ### don't go via QScriptValue
+            QScript::SaveFrameHelper saveFrame(engine, exec);
             QScriptValue tmp = engine->scriptValueFromJSCValue(arg0);
             QString propertyName(arg1.toString(exec));
             slot = engine->scriptValueToJSCValue(tmp.property(propertyName, QScriptValue::ResolvePrototype));
@@ -591,6 +592,7 @@ JSC::JSValue JSC_HOST_CALL functionConnect(JSC::ExecState *exec, JSC::JSObject *
             slot = arg1;
         else {
             // ### don't go via QScriptValue
+            QScript::SaveFrameHelper saveFrame(engine, exec);
             QScriptValue tmp = engine->scriptValueFromJSCValue(arg0);
             QString propertyName = arg1.toString(exec);
             slot = engine->scriptValueToJSCValue(tmp.property(propertyName, QScriptValue::ResolvePrototype));
diff --git a/src/script/api/qscriptengine_p.h b/src/script/api/qscriptengine_p.h
index c7db276..ec41cc9 100644
--- a/src/script/api/qscriptengine_p.h
+++ b/src/script/api/qscriptengine_p.h
@@ -265,6 +265,29 @@ public:
 #endif
 };
 
+namespace QScript
+{
+
+class SaveFrameHelper
+{
+public:
+    SaveFrameHelper(QScriptEnginePrivate *eng,
+                    JSC::ExecState *newFrame)
+        : engine(eng), oldFrame(eng->currentFrame)
+    {
+        eng->currentFrame = newFrame;
+    }
+    ~SaveFrameHelper()
+    {
+        engine->currentFrame = oldFrame;
+    }
+private:
+    QScriptEnginePrivate *engine;
+    JSC::ExecState *oldFrame;
+};
+
+} // namespace QScript
+
 inline QScriptValuePrivate *QScriptEnginePrivate::allocateScriptValuePrivate(size_t size)
 {
     if (freeScriptValues) {